# 19th Century Scientific Discoveries

Topics: Chemical element, Ralph Waldo Emerson, John Dalton Pages: 4 (1366 words) Published: June 22, 2013
“Science does not know it’s debt to imagination.” “Men love to wonder, and that is the seed of science.” Ralph Waldo Emerson was right on point when he said these two statements. There have been numerous great scientists that have come in and out of this world, and there are many to still come. When Emerson said these two quotes, he was talking about all of these scientists. The world we live in today would not be the same without the imagination and wonder of scientists; therefore we owe everything to imagination and wonder. Scientists have used their imagination to come up with some of the craziest ideas and experiments to try and find new discoveries and inventions in the world. During the 19th century, there were a lot of these new scientific discoveries. Some of these discoveries include Dalton’s Law of Partial Pressures, Dalton’s modern Atomic Theory, the Doppler Effect, James Prescott Joule’s and Helmholtz’s Law of Conservation of energy, Deiters’ presentation of the image of a nerve cell, Flemming’s description of mitosis, Darwin’s Theory of Evolution by natural selection, Rudolf Virchow’s belief that cells arise from pre-existing cells, Mendel’s laws of inheritance, Mendeleev’s Periodic Table, and the invention of cathode rays.

First, the two discoveries by John Dalton include his Law of Partial Pressures and his modern Atomic Theory. Dalton came up with his Law of Partial Pressures in 1801. This law states that the pressure of a mixture of gases is equal to the sum of the pressures of all the constituent gases alone. Mathematically it is expressed as: PressureTotal = Pressure1 + Pressure2 ... Pressuren. “Dalton's Law explains that the total pressure is equal to the sum of all of the pressures of the parts” (Unknown). The first part of Dalton’s atomic theory was published in 1808, and the second was in 1810. This theory can be summarized into five main points: “(1) atoms are tiny particles that make up elements; (2) atoms of a certain element are...

References: Arnold, Paul . "Famous Scientists: Walther Flemming and the Discovery of Mitosis." Bright Hub. 27 Apr. 2009. 17 Feb. 2013. <http://www.brighthub.com/science/genetics/articles/33094.aspx>.
1-Unknown. "Dalton 's Law of Partial Pressures." Exciting Gases. 17 Feb. 2013. <http://library.thinkquest.org/12596/dalton.html>.
2-Unknown. "Darwin 's Theory of Evolution-A Theory In Crisis." All About Science. 17 Feb. 2013. <http://www.darwins-theory-of-evolution.com/>.
3-Unknown. "Dmitri Medeleev." Kiwi Web-Chemistry & New Zealand. 17 Feb. 2013. <http://www.chemistry.co.nz/mendeleev.htm>.
1-Zorin, Danil . "History of Science." Informed By Nature. 2004. 17 Feb. 2013. <http://informedbynature.org/grdates/index/>.
2-Zorin, Danil . "Dalton’s Atomic Theory, 1808." Informed By Nature. 2004. 17 Feb. 2013. <http://informedbynature.org/grdates/grddetail/id/95>.
3-Zorin, Danil . "The Doppler Effect, 1842." Informed By Nature. 2004. 17 Feb. 2013. <http://informedbynature.org/grdates/grddetail/id/104>.
Sabbatini, Renato M.E.. "The History of its Discovery." Neurons and Synapses. 23 Feb. 2003. 17 Feb. 2013. <http://www.cerebromente.org.br/n17/history/neurons2_i.htm>.